I'll dump a few thoughts on this here.
First, I hope we can all agree that Destiny and now Destiny 2 are not strictly-speaking "competitive" games by what we've come to understand the title to mean. Competitive indicates, to me (and to a lot of others I would think) full support for ranked play, having custom / private matches, and of course providing dedicated servers to limit the amount of manipulation that can and does go on. And of course, a lot of competitive games put their competitive modes in the limelight -- that is to say, the single-player component (in Destiny's case, the cooperative component), either isn't there, or is not the star of the package.
Destiny kind of exists in a weird place where the people who play the PvP (myself included) are *super* passionate about it. We think it looks great, plays great, is skill-oriented, and even in the face of a lot of BS, we maintain it's half of that great experience you'll get when you play Destiny. Obviously a lot of this commentary is more directed towards Destiny 1 than 2, since most of us have only been exposed to these betas, but I think it is fair to say that 2 continues that feel, for the most part, and especially on PC where the gameplay is fast and very exciting. To us, things like Trials of Osiris and Iron Banner *are* competitive, and that's true even when when the game is proving to us just how little our personal investment matters.
Even with how much we love that experience, while competition absolutely exists in the Destiny-sphere, true competitive play is, to my knowledge, not actually a thing in Destiny 2, or won't be for a while if ever.
So I'd like an option to exist in the game for those casual players, and of course those who aren't comfortable with mouse and keyboard. If this exploit didn't exist, I would be more than happy to share that space with controller-using players. So my opinion at first was, hey, it's casual Destiny, who cares? But...
The video posted in the OP is not Destiny 1 AA. In the history of me playing, I have *never* had it work like that. That is actually broken. Maybe it's a bug. I have no clue, on earth, what that is, but it is not a way that console players can *possibly* enjoy the game. And that goes for M/K players, as well. If the choice is THAT, or M/K only, then it's an easy choice, and the AA has to go away. Completely. Period.
A subtler option would be one that I don't think Bungie would consider, which is simply to separate the play-spaces to a casual and competitive playlist (the latter of which would of course include IB and Trials of the nine) -- in the competitive playlist, MNK and controller can be supported, but with 0 aim assist. Bungie won't select this option because 1) It requires work, 2) it segments the player-base. There are more reasons, but those are the big two.
This is all of course in consideration of the people who are choosing and playing fairly. But clearly, there are people who are mixing both, and that's cheating, and that has to be fixed. With no clear option at hand for them to determine the inputs are going through third-party hardware, then whether or not Destiny is a competitive game, really doesn't matter. This limits the option, in my mind, to essentially providing the AA *only* for PvE, and removing it entirely from the PvP space.
That's not an option I like. I don't like it, because I have friends who would have benefited greatly from a little bit of *fair* AA and controller-usage, but as usual, other people figure out how to ruin it, and to me, now, in lieu of any better options that are cost-effective for Bungie to implement, I don't see any other way out of this mess. Because it's not even about losing, in reality, to someone abusing this stuff, it's about having a no-tolerance policy for cheating, and making your playerbase *feel* like you are watching their back. If you *think* people are cheating when they kill you, it's often as bad as actually having them cheat, from a subjective point-of-view.
In short, this situation sucks. Bungie pretty much has to get rid of this AA, completely, in D2. And that's bad, but having the conversations I have had with others, it feels like there's no real middle-ground here, as much as I feel like there should be.
